A case of hidradenoma papilliferum with transepidermal elimination

Transepidermal elimination is a process by which the skin eradicates undesirable or irritative dermal substances through intact epidermis or follicular epithelium by passive or active means. Although transepidermal elimination is being described in an increasing number and range of pathological processes, transepidermal elimination of hidradenoma papilliferum remains unrecorded to date in the Korean literature. We report a new case of hidradenoma papilliferum with transepidermal elimination. A 32-year-old woman presented with a bean-sized, protruding flesh red-colored nodule on the left labia major. The histologic finding of the lesion indicated a tubular and cystic structure microscopically expelled through the transepidermal canal.